Nullable return types in PHP7

PHP 7.1 Now supports nullable return types. The first RFC I linked to is the one they went for:

function nullOrString(int $foo) : ?string{    return $foo%2 ? "odd" : null;}

old answer:

Since my comment was actually an answer to the question:

PHP 7 won't support nullable return-types just yet, but there's an RFC out to address just that, it aims to land in PHP 7.1. If it passes, the syntax would then affect all type-hints (both return types and type-hints):

public function returnStringOrNull(?array $optionalArray) : ?string{    if ($optionalArray) {        return implode(', ', $optionalArray);//string returned here    }    return null;}

There's also a competing RFC to add union types, which would be able to do the same thing, but would look different:

public function returnStringOrNull(array|null $optionalArray) : string|null{    if ($optionalArray) {        return implode(', ', $optionalArray);//string returned here    }    return null;}

For now, though, you'll have to write:

public function returnStringOrNull( array $optionalArray = null){    if ($optionalArray) {        return implode(', ', $optionalArray);    }}

Or just return an empty string to be consistent with the return type, and check falsy value:

public function returnStringOrNull( array $optionalArray = null) : string{    if ($optionalArray) {        return implode(', ', $optionalArray);    }    return '';}//call$string = $x->returnStringOrNull();if (!$string) {    $string = $x->returnStringOrNull(range(1, 10));}

Nullable Types are available in PHP 7.1.

This is a syntax example:

public function getName(): ?string{    return $this->name; // name can be null}

PHP 7.1 is now GA and you can upgrade from PHP 7.0 (there are only few backward incompatible changes that you have to check)

It works with any type.
Example:

public function getOpportunity(): ?Opportunity{    return $this->opportunity;}